POD-11.08: Diabetes and Risk of Death from Cancer of the Prostate, Kidney, and Urinary Bladder

Diabetes mellitus and the risk of bladder cancer: A PRISMA-compliant meta-analysis of cohort studies

BACKGROUND

Epidemiologic studies have reported inconsistent results regarding the relationship between diabetes mellitus (DM) and the incidence of bladder cancer. This comprehensive systematic review and meta-analysis explored and evaluated this relationship in participants with different characteristics.

METHODS

Studies indexed in the PubMed, Embase, and the Cochrane Library databases that compared bladder cancer incidence mortality between DM and non-DM participants were included in the present study. The relative risks (RRs) of a random-effects model were used to assess these associations.

RESULTS

The final analysis included 21 cohort studies, involving a total of 13,505,643 participants. Overall, DM was associated with an increased risk of bladder cancer or cancer mortality when compared with non-DM participants (RR: 1.23; 95% confidence interval [CI]: 1.12-1.35; P < .001). Furthermore, DM had a harmful impact on subsequent bladder cancer risk in men compared with those without DM (RR: 1.23; 95% CI: 1.06-1.42; P = .005), whereas no significant relationship was observed between DM and bladder cancer in women (RR: 1.24; 95% CI: 0.95-1.61; P = .119). There was no significant gender difference for this relationship (ratio of RR: 0.99; 95% CI: 0.73-1.34; P = .958). In addition, cancer incidence (RR: 1.21; 95% CI: 1.09-1.35; P < .001) and cancer mortality (RR: 1.25; 1.17-1.35; P < .001) both increased in DM patients. Finally, smoking status and follow-up duration might also affect this relationship in men and women.

CONCLUSIONS

The findings of this study indicated that DM was associated with elevated bladder cancer or cancer mortality risk, especially in men. This relationship in women requires further exploration.

Diabetes and kidney cancer outcomes: a propensity score analysis

There is conflicting evidence whether diabetes is associated with survival outcomes in patients undergoing a nephrectomy for renal cell carcinoma. We performed a retrospective review of 1034 patients undergoing nephrectomy for unilateral, M0, renal cell carcinoma between 2000 and 2016 at a tertiary academic center. Inverse probability of treatment weights were derived from a propensity score model based on various clinical, surgical, and pathological characteristics. We used Cox proportional hazard models to evaluate the association between diabetes and disease-free survival, cancer-specific survival, and overall survival in the sample weighted by the inverse probability of treatment weights. Furthermore, to evaluate whether severity of diabetes was associated with survival outcomes, we performed separate analyses where inverse probability of treatment weights were computed based on the probability of having diabetes that was controlled by medication. Of the 1034 patients, 180 (17 %) had diabetes. Of these, 139 (77 %) patients required medications for diabetes control while the remaining 41 (23 %) had diet controlled diabetes. Median follow-up was 50 months (IQR 17-86). Diabetes at the time of surgery was not significantly associated with disease-free survival (HR 1.11, 95 % CI 0.64 -1.91), cancer-specific survival (HR 0.96, 95 % CI 0.49-1.91), or overall survival (HR 1.28, 95 % CI 0.84-1.95). We found similar results when we compared diabetics controlled with medication vs. non-diabetics or diet controlled diabetics. In summary, we found no significant association between diabetes and survival outcomes in patients undergoing nephrectomy for M0 renal cell carcinoma. These results suggest that diabetics should be treated and followed in a similar manner to non-diabetics.

Prediabetes and the risk of cancer: a meta-analysis

AIMS/HYPOTHESIS

The results from prospective cohort studies of prediabetes (impaired fasting glucose and/or impaired glucose tolerance) and risk of cancer are controversial. We conducted a meta-analysis to evaluate the risk of cancer in association with impaired fasting glucose and impaired glucose tolerance.

METHODS

The PubMed, EMBASE and Cochrane Library databases were searched for prospective cohort studies with data on prediabetes and cancer. Two independent reviewers assessed the reports and extracted the data. Prospective studies were included if they reported adjusted RRs with 95% CIs for the association between cancer and prediabetes. Subgroup analyses were conducted according to endpoint, age, sex, ethnicity, duration of follow-up and study characteristics.

RESULTS

Data from 891,426 participants were derived from 16 prospective cohort studies. Prediabetes was associated with an increased risk of cancer overall (RR 1.15; 95% CI 1.06, 1.23). The results were consistent across cancer endpoint, age, duration of follow-up and ethnicity. There was no significant difference for the risk of cancer with different definitions of prediabetes. In a site-specific cancer analysis, prediabetes was significantly associated with increased risks of cancer of the stomach/colorectum, liver, pancreas, breast and endometrium (all p < 0.05), but not associated with cancer of the bronchus/lung, prostate, ovary, kidney or bladder. The risks of site-specific cancer were significantly different (p = 0.01) and were highest for liver, endometrial and stomach/colorectal cancer.

CONCLUSIONS/INTERPRETATION

Overall, prediabetes was associated with an increased risk of cancer, especially liver, endometrial and stomach/colorectal cancer.

Risk of bladder cancer in patients with diabetes mellitus: an updated meta-analysis of 36 observational studies

BACKGROUND

Increasing evidence suggests that a history of diabetes mellitus (DM) may be associated with an increased risk of bladder cancer. We performed a systematic review with meta-analysis to explore this relationship.

METHODS

We identified studies by a literature search of Medline (from 1 January 1966) and EMBASE (from 1 January 1974), through 29 February 2012, and by searching the reference lists of pertinent articles. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were calculated with a random-effects model.

RESULTS

A total of 36 studies (9 case-control studies, 19 cohort studies and 8 cohort studies of patients with diabetes) fulfilled the inclusion criteria. Analysis of all studies showed that DM was associated with an increased risk of bladder cancer (the summary RR = 1.35, 95% CI 1.17-1.56, p < 0.001, I2 = 94.7%). In analysis stratified by study design, diabetes was positively associated with risk of bladder cancer in case-control studies (RR = 1.45, 95% CI 1.13-1.86, p = 0.005, I2 = 63.8%) and cohort studies (RR = 1.35, 95% CI 1.12-1.62, p < 0.001, I2 = 94.3%), but not in cohort studies of diabetic patients (RR = 1.25, 95% CI 0.86-1.81, p < 0.001, I2 = 97.4%). The RRs of bladder cancer were 1.38 (1.08-1.78) for men and 1.38 (0.90-2.10) for women with diabetes, respectively. Noteworthy, the relative risk of bladder cancer was negatively correlated with the duration of DM, with the higher risk of bladder cancer found among patients diagnosed within less than 5 years.

CONCLUSIONS

These findings support the hypothesis that men with diabetes have a modestly increased risk of bladder cancer, while women with diabetes were not the case.

Diabetes mellitus and risk of bladder cancer: a meta-analysis of cohort studies

Background

Increasing evidence suggests that diabetes mellitus (DM) may be associated with an increased risk of bladder cancer. To provide a quantitative assessment of this association, we evaluated the relation between DM and incidence and mortality of bladder cancer in an updated meta-analysis of cohort studies.

Methods We identified cohort studies by searching the EMBASE and MEDLINE databases, through 31 March 2012. Summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated with random-effects models.

Results

A total of 29 cohort studies (27 articles) were included in this meta-analysis. DM was associated with an increased incidence of bladder cancer (RR 1.29, 95% CI: 1.08–1.54), with significant evidence of heterogeneity among these studies (p<0.001, I² = 94.9%). In stratified analysis, the RRs of bladder cancer were 1.36 (1.05–1.77) for diabetic men and 1.28 (0.75–2.19) for diabetic women, respectively. DM was also positively associated with bladder cancer mortality (RR 1.33, 95% CI: 1.14–1.55), with evident heterogeneity between studies (p = 0.002, I² = 63.3%). The positive association was observed for both men (RR 1.54, 95% CI: 1.30–1.82) and women (RR 1.50, 95% CI: 1.05–2.14).

Conclusion

These findings suggest that compared to non-diabetic individuals, diabetic individuals have an increased incidence and mortality of bladder cancer.